1. Field of the Invention
The present invention generally relates to encoding and decoding in data communications and more particularly, to a novel encoding and decoding method and associated architectures for processing information bits with different modulation and coding.
2. Description of the Related Art
In wireless communications, dynamic adjustment or switching of modulation schemes and channel coding can yield better performance or system throughput when channel (or data path) conditions vary. When channel conditions are relatively adverse, modulation and coding are respectively adjusted to lower-order modulation schemes and lower-rate coding. Conversely, when channel conditions are relatively favorable, modulation and coding are respectively adjusted to higher-order modulation schemes and higher-rate coding. Exemplary lower-order modulation schemes in the art include quaternary phase shift keying or QPSK. Exemplary higher-order modulation schemes include quadrature amplitude modulation or QAM. As information are being transmitted between a source (e.g., a base station) and a destination (e.g., a mobile device), the channel conditions are monitored for determining whether adjustment of the modulation and coding is needed.
Similar to the data transmission via the wireline, wireless transmission of a particular packet or data may not succeed at the first instance due to interference in the channel. Multiple transmissions of the same data can improve system performance particularly if the receiver can combine multiple transmissions for demodulating and decoding the signals. However, such combining in the prior art only applies to signals with the same modulation and channel coding schemes. Thus there exists a dilemma that either 1) the transmitter will have to change the modulation and/or coding according to the channel conditions with the receiver abandoning previously received signals of the same information, or 2) the transmitter will have to maintain the same modulation and coding until the packet or burst of data is successfully received.
There is therefore a need for a novel encoding and decoding method and associated architectures for processing data with different modulation and coding that advantageously overcome the signal combining problems and other problems in the art as set forth herein.